Floral structure of Mesanthemum radicans (Eriocaulaceae, Poales): morphological and anatomical novelties

2021 ◽  
Vol 139 ◽  
pp. 306-317
Author(s):  
Arthur de Lima Silva ◽  
Thomas Stützel ◽  
Marcelo Trovó ◽  
Alessandra Ike Coan
Keyword(s):  
Floral Structure

Reproductive Biology and Floral Phenologies of the Sympatric Species Leptospermum myrsinoides and L. continentale (Myrtaceae)

1993 ◽  
Vol 41 (5) ◽  
pp. 527 ◽  
Author(s):  
SP Obrien ◽  
DM Calder
Keyword(s):  
Flowering Time ◽  
Genetic Control ◽  
Reproductive Biology ◽  
Pollen Viability ◽  
Sympatric Species ◽  
Anther Dehiscence ◽  
Floral Structure ◽  
Days After Anthesis ◽  
Degree Of Overlap

The reproductive biology and floral phenologies of co-occurring Leptospermum myrsinoides and L. continentale were investigated. Both species have similar floral structure and both are protandrous. Anther dehiscence is staggered over approximately 6 days and pollen viability remains high for at least 3 days. The styles of both species are short at anthesis but extend during the next 6 days to approximately the same height as the anthers. The stigmas of these species do not achieve maximum receptivity until at least 4 days after anthesis. Both species are self-compatible. At the three sites studied, L. myrsinoides and L. continentale have separate flowering times with L. myrsinoides always flowering first. Within populations of each species, plants reached first flower and peak flower in the same order in 1989 and 1990, implying genetic control over flowering time. It is suggested that protandry in these species enhances the likelihood of outcrossing and the staggered release of pollen coupled with the degree of overlap within flowering populations increases the number of potential mates available to each flower.

Impatiens megamalayana, a new species of Impatiens from the Western Ghats, Tamil Nadu, India

Phytotaxa ◽  
2017 ◽  
Vol 302 (2) ◽  
pp. 193 ◽  
Author(s):  
R. RAMASUBBU ◽  
C. DIVYA ◽  
N. SASI KALA ◽  
ANJANA SURENDRAN ◽  
A.K. SREEKALA
Keyword(s):  
New Species ◽  
Western Ghats ◽  
Tamil Nadu ◽  
Pollen Grains ◽  
Critically Endangered ◽  
Floral Structure ◽  
Effective Strategies ◽  
The Western Ghats ◽  
A New Species

Impatiens megamalayana, a new species from Tamil Nadu, India is described and illustrated. This species is characterized by a ridged stem, ensiform and villous leaves, a wrinkled boat-shaped lower sepal with outwardly curved tip, ornamented seeds and strictly ovate pollen grains. This combination of characters makes determining the relationships of I. megamalayana difficult. The floral structure of I. megamalayana is closely allied to I. herbicola Hook.f. and I. inconspicua Benth. in Wall., the latter with three varieties, but it differs by several unique vegetative and floral features. Impatiens megamalayana is assessed as Critically Endangered in accordance with the IUCN guidelines. The habitat of the species is severely affected by landslides. As a result, effective strategies should be developed to protect I. megamalayana from exinction.

Floral structure and pollination in Pelargonium

1996 ◽  
pp. 631-638 ◽  
Author(s):  
M. Struck ◽  
J. J. A. Van der Walt
Keyword(s):  
Floral Structure

scholarly journals Butterfly-wing pollination in Scadoxus and other South African Amaryllidaceae

2020 ◽  
Vol 193 (3) ◽  
pp. 363-374 ◽  
Author(s):  
Hannah C Butler ◽  
Steven D Johnson
Keyword(s):  
South African ◽  
Ventral Surface ◽  
Butterfly Wing ◽  
Pollen Transfer ◽  
Floral Structure ◽  
Pollination Mechanisms ◽  
Butterfly Wings ◽  
Floral Diversification ◽  
Swallowtail Butterflies ◽  
Transfer Mechanisms

Abstract Understanding the evolution of floral morphology requires information about the identity of pollinators as well as the specific mechanisms of pollen transfer. Based on preliminary field observations and floral structure, we hypothesized that pollination mechanisms involving the transfer of pollen on butterfly wings occur in several lineages of South African Amaryllidaceae. Here we report findings from a detailed study of butterfly-wing pollination in two subspecies of Scadoxus multiflorus and review the prevalence of this pollination mechanism among other Amaryllidaceae in southern Africa. We established that S. multiflorus subsp. katherinae is genetically self-incompatible and thus entirely reliant on pollinators for seed production. We determined that this subspecies is pollinated almost exclusively by large swallowtail butterflies, principally males of the mocker swallowtail Papilio dardanus cenea. Flowers of S. multiflorus subsp. multiflorus are pollinated by pierid and swallowtail butterflies. Pollen is deposited on the ventral surface of the wings of butterflies as they flutter over the strongly exserted stamens. We predict that butterfly-wing pollination occurs in at least nine species of South African Amaryllidaceae, which may reflect several independent origins of this mechanism. The flowers of these species are red or orange with strong herkogamy and are either bowl-brush or open-brush in shape. We provide maps of the distribution of pollen on the ventral surface of the wings of pollinators for four of these species. All four appear to be pollinated via the ventral surface of large butterfly wings, with the floral structure facilitating the process. These findings illustrate the importance of investigating pollen transfer mechanisms in order to understand patterns of floral diversification and floral convergence.

Analysis of the bacterial floral structure and diversity of Xuanwei ham by 16S rDNA sequencing

2020 ◽  
Vol 40 (4) ◽  
Author(s):  
Luying Shan ◽  
Yinjiao Li ◽  
Shi Zheng ◽  
Yuanmiao Wei ◽  
Ying Shang
Keyword(s):  
16S Rdna ◽  
16S Rdna Sequencing ◽  
Floral Structure ◽  
Rdna Sequencing

scholarly journals The synstigma turns the fig into a large flower

2020 ◽  
Vol 195 (1) ◽  
pp. 93-105
Author(s):  
Simone P Teixeira ◽  
Marina F B Costa ◽  
João Paulo Basso-Alves ◽  
Finn Kjellberg ◽  
Rodrigo A S Pereira
Keyword(s):  
Pollen Tube ◽  
Pollen Grains ◽  
Pollen Tubes ◽  
Live Cells ◽  
Fig Wasp ◽  
Fig Wasps ◽  
Floral Structure ◽  
Transmitting Tissue ◽  
Transmission Electron ◽  
Large Flower

Abstract The synstigma is a structure formed by clusters of two to several stigmas, whether in the same or between different flowers. Although rare in angiosperms, synstigmas are found in c. 500 out of the c. 750 Ficus spp. (Moraceae). This floral structure is associated with fig-fig wasp pollinating mutualism. The synstigma structure and pollen tube pathways were studied in six Ficus spp. from Ficus section Americanae to test the hypothesis that the synstigma allows pollen grains deposited on a stigma to emit pollen tubes that can grow laterally and fertilize surrounding flowers. Syconia containing recently pollinated stigmas were collected and dissected, and the stigmas were processed for analyses with light and scanning and transmission electron microscopy. The arrangement of the synstigmas across species can be spaced or congested, with the number of stigmas per synstigma ranging from two to 20. Contact between the stigmas in a synstigma occurs by the intertwining of the stigmatic branches and papillae; their union is firm or loose. The pollen tube grows through live cells of the transmitting tissue until reaching the ovule micropyle. Curved pollen tubes growing from one stigma to another were observed in five out of the six species studied. The curvilinear morphology of pollen tubes probably results from competition by pollen between the stigmas composing a synstigma via chemotropic signals. The synstigma appears to be a key adaptation that ensures seed production by flowers not exploited by the fig wasps in actively pollinated Ficus spp.

Floral structure in Thismia (Thismiaceae: Dioscoreales): new insights from anatomy, vasculature and development

2020 ◽  
Author(s):  
Maxim S Nuraliev ◽  
Sophia V Yudina ◽  
Ekaterina A Shepeleva ◽  
Ba Vuong Truong ◽  
Thi Xuyen Do ◽  
...  
Keyword(s):  
Distal Part ◽  
Floral Development ◽  
Floral Morphology ◽  
Reproductive Organs ◽  
Floral Structure ◽  
Interspecific Differences ◽  
Precise Understanding ◽  
Floral Vasculature ◽  
General Appearance ◽  
Comprehensive Study

Abstract Thismia is characterized by an exceptionally complicated floral morphology that is currently not understood properly. In the taxonomic literature, descriptive rather than morphological terms are often applied to parts of the flower in Thismia, relating to the general appearance of the floral organs instead of their precise homologies. Precise understanding of the floral structure is complicated by the rarity of Thismia spp. and the paucity of appropriate material. Here we provide a comprehensive study of reproductive organs of three Thismia spp. (T. annamensis, T. javanica and T. mucronata) including the first investigation of inflorescence architecture and early floral development in Thismiaceae. We found a hitherto unknown diversity of the reproductive shoots in the genus, manifested in the number of floral prophylls (two or three, in contrast to a single prophyll in the vast majority of monocots) and in the branching plane resulting in two distinct inflorescence types, a drepanium and a bostryx. We report the non-acropetal sequence of initiation of floral whorls (with stamens being the last elements to initiate), never previously described in monocots, and the gynoecium composed of completely plicate carpels, also a rare feature for monocots. Floral vasculature is relatively uniform in Thismia, but significant interspecific differences are found in tepal innervation, including the number of tepal traces; some of these differences are not immediately related to the external tepal morphology. We argue that the annulus, which acts as a roof of the hypanthium, possesses an androecium nature and represents congenitally fused bases of stamen filaments. We describe the stamens as laminar structures, which are also shortly tubular in the distal part of the supraconnective with the adaxial tubular side forming a skirt-like appendage. Finally, the placentas, which are column-like when mature, are initially parietal, becoming secondarily similar to free-central placentas through schizogenous separation from the ovary wall.

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